A typical friction clutch pack includes multiple friction plates interleaved along its axis. The friction clutch pack is actuated by the application of an axial force to the friction plates that compresses the friction plates and clamps them together. With the friction plates clamped together, rotary movement can be transferred through the friction clutch pack via the friction plates.
Ball ramp actuators are commonly used to generate the axial force used for actuating friction clutch packs. A ball ramp actuator includes a ball ramp with two opposing ball ramp halves supported along an axis for relative rotation, load transferring balls positioned in respective ramped ball receiving recesses defined between the two ball ramp halves, and an apply plate coupled to one of the two ball ramp halves.
Typically a ball ramp actuator includes two ball ramp plates that respectively correspond to the two ball ramp halves, with the apply plate coupled to one of the two ball ramp plates. Upon relative rotation of the two ball ramp plates, each load transferring ball climbs its respective ramped ball receiving recess, which axially displaces the two ball ramp plates and generates an axial force at the apply plate. In application, the ball ramp actuator is axially aligned with the friction clutch pack, with the apply plate arranged to actuate the friction clutch pack by applying its axial force to the friction clutch pack's friction plates.